Matrix-retainer.



PATENTED SEPT. 26, 1905.

J MILLS MATRIX RETAINER.

APPLICATION rum) Jun 11. 1904.

UNITED sTA Es PATENT OFFICE.

JOHN MILLS, OF BRANTFORD,' CANADA.

MATRIX-RETAINER."

Specification of Letters Patent.

Patented Sept. 26, 1905.

To all whom it may concern:

. Be it known that I, JOHN MILLS, of the city of Brantford, in thecounty of Brant, Province of Ontario, Canada, have invented certain newand useful Improvements in Matrix-Retainers, of which the following isaspecification.

- The object of my invention is to devise a simple and effectivematrix-retainer adapted for use in a varietyof situations and of neatand convenient form; and it consists, essentially, of a bar having arms.slidable thereon, the'arms being adapted at their free ends to carryboth ball-and-socket and rigid jaws, substantially as hereinafter morespecifically described and then definitely claimed.

Figure 1 is a perspective View of my improved retainer. Fig. 2 is asectional elevation of one of the arms of the same. Fig. 3 is aperspective detail of a form of jaw used in clamping a matrix about atooth. Fig. 4-. is an elevation of the apparatus, showing at the lefthand a rigid jaw, such as used in clamping a matrix round a tooth, andat the right hand the rigid jaw employed when spreading apart the endsof aretainer, as calledfor in placing a matrix behindand between thefront teeth. Fig. 5 is a perspective detail of a modification of myinvention. Fig. .6 is a sectional detail showing one of the armsprovided with a set-screw by means of which it may be clamped to the'bar.

In the drawings like letters of reference indicate corresponding partsin the difiierent figures.

Referring particularly to Fig. 1, A is a bar, and B B arms, eachprovided at one end with jaws embracing the bar A. On each armbetweenthe jaws I pivot a block C, preferably slightly concave on its underside, so as to present two transverse edges engaging the upper side ofthe bar. I find this arrangement preferable to having the bar passthrough a slot cut through a solid end of the arm, as shown inFig. 5.

From the construction described it follows that each arm may be readilyslid along the bar by pressure applied in line with the bar. Thepressure applied at the end of the arm rocks the arm on the bar so thatone of the edges of the lower side of the opening between the jaws andthe opposite edges of the block C engage the lower and upper surfaces ofthe bar, and by their frictional contact grip the bar so-firmly that nomatter how great the pressure applied to the end of the arm it will notslip on the bar. Indeed, the greater the pressure the firmer the griptaken of the bar.

For the purpose of enabling the arms to be moved I provide studs (0 onthe arms in line withthe bar. These may be engaged by suit able forcepsto draw the arms together or spread them apart. The outer end of eacharm has a hole'b zbored therein substantially parallel to the 'bar A.Through the lower end of the bar is threaded a screw D. The upper end ofthis screw is cupped, and asimilar cup is formed opposite to it at theupper side of the hole 6.

The jaws E have ball-ended stems 0 secured to their rear sides. Theseballs are inserted into the holes 6 until they come in line with thecups already described. The said screws are then tightened up to engagethe ball. A simply-constructed and reflective ball-joint is thusformedfor the jaws'E, which any time may be made rigid by further tighteningup the screws D.

I claim nothing on the configuration of the jaws E, as they aresubstantially the same as those shownin my prior United States patent,No. 719,834.

For certain purposes it is necessary to provide jaws for clamping a bandround a tooth. For such purposes I employ a jaw F, which is providedwith a stem 01 and a chisel ende.

In working on front teeth it is sometimes I necessary to have jaws whichmay be engaged with the ends of amatrix-band to spread them outwardly.For this purpose I employ a jaw G, such as shown at the right hand inFig. 4:. This is also provided with a stem d and at its outer end a pinf, which may be engaged with holes punched in a matrix-band.

The jaws F and G are held in position by insertingtheir stems in theholes band tightening up the screws D.

It will thus be seen that the-construction I I have devised enables meto connect either rigid or ball-aiid-socket jaws to the ends of the armsB, thus enabling the one tool to be adapted for a variety of purposes.

I do not claim as new the methods of using- It is of course notabsolutely necessary that both arms B be made movable on the bar A, andin Fig. 5 I have shown only one arm so movable. In this figure, further,I show one set of jaws similar to jaws Gr, permanently secured to theends of the arms B. A tool as thus constructed is of course limited inits use, being particularly intended for applying bands to the frontteeth.

In Fig. 6 I show a set-screw by means of which one of the arms may beclamped to the bar at any time, so that when the forceps are applied toclamp the jaws on a band only one ofthe arms will slide. This is animportant matter when working in some positions.

What I claim as my invention is-.

1. In amatriX-retainer a bar in combination with arms slidable on thebar means whereby the arms are adapted to grip it when rocked in linetherewith; and matrix-engaging jaws connected to the ends of the arms,substantially as described.

2. In a matriX-retainera bar in combination with arms slidable on thebar means whereby the arms are adapted to grip it when rocked in linetherewith; matrix-engaging jaws connected to the ends of the arms; andstuds on sides of the arms adjacent to the bar for engagement byforceps, substantially as described.

3. In a matrix-retainer a bar in combination with an arm suitablyconnected with the bar; an arm slidable on the bar means whereby thearms are adapted to grip it when rocked in line therewith; andmatrix-engaging jaws connectedto the ends of the arms, substantially asdescribed.

4. In a matrix-retainer a bar in combination with an arm suitablyconnected with the bar; an arm slidable on the bar'means whereby thearms are adapted to grip it when rocked in line therewith;matrix-engaging jaws connected to the ends of the arms; and studs onsides of the arms adjacent to the bar for engagement by forceps,substantially as described.

5. In amatriX-retainer a bar in combination with an arm suitablyconnected with the bar, the arms having holesbored through their ends inthe plane of the bar; a cup formed at one side of each hole; a cuppedscrew threaded through each arm to cooperate with the cups in the holesto form ball-sockets; and jaws provided with balls adapted to be engagedby the said ball-sockets, substantially as described.

6. In a matrix-retainer a bar in combination with an arm suitablyconnected with the bar, the arms having holes at right angles theretobored through their ends in the plane of the bar; screws threadedthrough the arms into the holes; and jaws having stems adapted to enterthe said holes, substantially as described.

7. In a matrix-retainer an arm having ahole bored transversely throughits end; and having a cup formed at one side of the hole in combinationwith a cup-ended screw threaded through the arm into the hole oppositethe aforesaid cup to coaet with said cup in engaging a ball,substantially as described.

8. In amatrix-retainer a bar in combination with an arm suitablyconnected with the bar; an arm forked to embrace the bar; a blockpivoted between the jaws and shaped to engage the bar; andmatrix-retaining jaws at the ends of the arms, substantially asdescribed.

9. In a matrix-retainer a bar in combination with an arm suitablyconnected with the bar; an arm forked to embrace the bar; a blockpivoted between the jaws and shaped to engage the bar, with a pluralityof knife-edges; and matrix-retaining jaws at the ends of the arms,substantially as described.

10. In a matrix-retainer a bar in combination with arms slidable on thebar means whereby the arms are adapted to grip it when rocked in linetherewith; matrix-engaging jaws connected to the ends of the arms; and aset-screw whereby one of the arms may be clamped to the bar,substantially as described.

11. In a matrix-retainer a bar in combination with an arm suitablyconnected with the bar; an arm slidable on the bar and provided with aset-screw whereby it may be clamped to the bar; and matrix-engaging jawsconnected to the ends of the arms, substantially as described.

Brantford, Ontario, May 17, 1904.

JOHN MILLS.

In presence of D. B. MOORE, IRENE BAXTER.

